1. Field
The technical field relates to a gamma correction system and method for a display device, and more particularly, to a correction system and method for correcting luminance dispersion for each luminance adjustment step in a display device.
2. Description of the Related Technology
In order to ensure image quality of a display device to comply with technical specifications or warranties associated with a product, during a manufacturing process of the display device the display device is subject to adjustment processes for insuring luminance, accuracy of a color coordinate for reference luminance value, and dispersion or deviation of luminance which may occur in each pixel due to a low temperature poly-silicon (LTPS) process and a deposition process.
Generally, an example process for correcting dispersion or deviation of luminance in a display module of a display device includes a method of including a luminance table having several luminance adjustment steps, consecutively correcting optical characteristics such as luminance and a color coordinate based on a reference luminance adjustment step for each selected luminance value, and performing correction for other luminance adjustment steps by applying a correction equation based on the corrected optical characteristics.
That is, compensation is generally performed by obtaining a difference in gamma data which occurs as reference luminance value is corrected, e.g., luminance dispersion and applying the difference multiplied by a luminance ratio to other luminance adjustment steps.
Optical characteristics corresponding to the reference luminance value can be stably measured and thus a substantially accurate correction for the reference luminance value may be achieved. However, a variation in the optical characteristic may increase due to a change of the optical characteristics resulting from the LTPS processing of a material or dispersion of a material when applying the correction method to luminance adjustment steps other than the reference luminance value. The greater difference from the reference luminance value a luminance value has, the greater the variation in the optical characteristic increases.
Since in many cases, the reference luminance value is the maximum luminance value, particularly in the case where a luminance adjustment step value is low, a variation in the optical characteristic thereof is at a level which is difficult to predict, and thus efficiency of a process for correcting luminance dispersion may be greatly reduced. As a result, correction of dispersion or deviation of luminance using a minimum number of luminance adjustment steps cannot be performed.
Therefore, a method of compensating luminance deviation that can minimize the variation in the optical characteristic in the luminance adjustment steps other than the reference luminance value adjustment step in the display device and substantially correct the dispersion or deviation of luminance so as to produce a display device having uniform optical characteristics for each luminance and reliable image quality is desirable.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.